程琳燕,李磊,高毅凡,等. 琼东南盆地陵水凹陷海底周期阶坎底形的特征及成因[J]. 海洋地质与第四纪地质,2022,42(1): 37-44. DOI: 10.16562/j.cnki.0256-1492.2021041902
引用本文: 程琳燕,李磊,高毅凡,等. 琼东南盆地陵水凹陷海底周期阶坎底形的特征及成因[J]. 海洋地质与第四纪地质,2022,42(1): 37-44. DOI: 10.16562/j.cnki.0256-1492.2021041902
CHENG Linyan,LI Lei,GAO Yifan,et al. The characteristics and genesis of bottom cyclic steps in the Lingshui Sag of Qiongdongnan Basin[J]. Marine Geology & Quaternary Geology,2022,42(1):37-44. DOI: 10.16562/j.cnki.0256-1492.2021041902
Citation: CHENG Linyan,LI Lei,GAO Yifan,et al. The characteristics and genesis of bottom cyclic steps in the Lingshui Sag of Qiongdongnan Basin[J]. Marine Geology & Quaternary Geology,2022,42(1):37-44. DOI: 10.16562/j.cnki.0256-1492.2021041902

琼东南盆地陵水凹陷海底周期阶坎底形的特征及成因

The characteristics and genesis of bottom cyclic steps in the Lingshui Sag of Qiongdongnan Basin

  • 摘要: 海底周期阶坎底形一直是海洋地质关注的热点。本文基于285 km2三维地震资料对琼东南盆地海底周期阶坎底形几何构型(波长、波高、迎流面长度、背流面长度、迎流面夹角和背流面夹角)及形成机理进行了分析。研究区位于上陆坡(2°~14°),发育一条NE-SW水道,宽 6.5 km,深 35 m。水道内外均发育周期阶坎,剖面上具有波状特征。周期阶坎的波长(20~160 m)随深度增加而变长,波高(4~10 m)随深度增加而减小,迎流面长度(20~140 m)比背流面长度(10~40 m)长,迎流面夹角(0.1°~0.15°)平缓,背流面夹角(0.2°~0.8°)陡峭。初步认为,研究区周期阶坎底形由持续稳定的浊流形成,且以沉积型周期阶坎为主。

     

    Abstract: Cyclic steps, as a kind of bedforms on the deep sea bottom, are one of the hot research spots in deep sea geology nowadays. Based on the 285 km2 of 3D seismic data collected from the Qiongdongnan Basin, the characteristics of cyclic steps, such as the wavelength, wave height, length of lee side, length of steep side, angle of lee side and angle of steep side, as well as their forming mechanisms are carefully analyzed in this paper. The study area is located on the upper slope (2°~14°), with a NE-SW channel of 6.5 km in width and 35 m in depth. Cyclic steps are developed on both inner and outer sides of the channel, with wavy patterns on profile. Wavelength (20~160 m) increases, while wave height (4~10 m) decreases with depth, the length of the leeward side (20~140 m) is longer than that of the windward (10~40 m), the leeward side is gentle (0.05°~0.06°), but windward side steep (0.1°~0.35°). It is suggested that most of the cyclic steps be formed by the deposition of a continuous and stable turbidity current.

     

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